Well, after wasting almost 3 years of my life treadin' water at a so-called "good Union Grocery Job", I'm out and happier than ever! Been waitin' tables for the last 18 months and buyin' parts/pieces at a downright scary (read "normal") rate. Anyway I got very lucky on a pair of Innovative Turbo T76's, ball-bearing units with Q-trim turbines, .96 A/R's to start with. I am hoping somebody has some insight as to how well these will be spooled by my 406, spec's are as follows:

3550lbs raceweight, '68 Chevelle
8.5:1 C.R.
5.85" rod length
AFR 210 Elim's (Comp. ported version) or 227's if that sounds like a better fit
Duttweiler SR by Comp Cams 236/242, lobes 4873s/4874s, appx. .600 lift (damn it, cam card is at the shop, haven't memorized it, yet)
Car will always be a stick-shift application
Plan is 6psi "driving", 10psi Summer "driving", 15-20psi @ full-tilt track outing (after a year or more of T-n-T, that is!!)
Lookin' for 4-digit power at the wheels (I don't think I've ever actually posted that until now, that's weird. )

Any and all info' is welcome, I know how much knowledge is on this site, hasn't led me astray yet.


---==Temio Williams
Yuba City, CA

 

you will need more than 20 psi to do that.
what fuel ?

 

ohh, and the Q trim will make good torque down low in rpm

 

Fuel here is CA 91octane (water/piss) for the daily drive, C12 or C16 on track days. I know what you mean about more than 20psi, whatever the boost is will be fine (I had thought more like 24-25psi), car will be tuned on a Dynojet, MSD 7535 & AMS-1000 also. The guy I got the turbos from had them on a 406 as well, more cam though (255/260 @ .050") in a lighter chassis, ran low-8's @173mph on small tire. I'm shootin' for single-digits as well, although low-8's is a little outta' my league! Thank you for the input,


---==Temio Williams
Yuba City, CA

 

Bump the cam up 10-12 degs duration to get abit more rpm out of that combo. I see those turbos coming on in the mid high 4000 rpm range so you will want to get them running in the 6000+ rpm range for peak power to get some use out of them. Thats going to require a ~250 deg solid roller.

210 heads with 2.08 valve should do the numbers while keeping all 23 deg sbc stuff. 227's require special parts/lifters etc. Not worth the hassle IMO for those numbers.

 

The cam's a tick larger than a similar Duttweiler build with PT67's, made 1000+ @ 5900rpm, albeit at only 230*@.050". I would like the turbos to come on a little earlier than 4000rpm, could I tailor the hit with some .81 A/R housings to replace the .96's? Are those as easy to find as the turbines for the P-Trim wheel? I figured on launchin' on the 2-Step at around 3800rpm/8psi to start, see where I can go from there. Ditto on the 210's, they've been kinda' my sweet spot as far as the "want" list, 308/235 @ .600", strong mid-lift flow too (standard AFR qualities) all for <$2K.


---==Temio Williams
Yuba City, CA

 

With a 2 step they may come alive more. Not sure what rpm would be best for you to launch but all the 6 spd guys I know launch around 85-90% of peak hp rpm and do a quick slip. With boosted power it may not need to be that high but it will need to be determined by you at the track.

On the street however, you wont be using that 2 step so spool will be delayed. .96 housings on T70's on a 406 here was said to be starting to get into boost by mid 4000 rpm range and that guy had a bigger heads/cam setup than you are planning. 76's I can imagine to be alittle higher than that so I think .81 housings would be much better for that combo and a tick larger cam. Just my opinion.

 

Good info', I got lucky on the cam on Ebay, of all places, so if the need arises to get a custom unit ground, I can call Cam Motion or Comp for somethin' a little hairier.


---==Temio Williams
Yuba City, CA

 

I'll probably end up in 4th through the traps, any ideas as to what rearend gear ratio would put me trippin' the beams @ 6500rpm? 1:1 is 4th gear, thought I had the calculator for computing this in my favorites page but ?? I played around with the Keisler Speed Analyzer charts and think I came up with 3.31's with a 28" tire = 6500rpm @ 158mph? Wow, I'm sleepy. Thank you for any and all help!


---==Temio Williams
Yuba City, CA

 

they don't make Q trim turbonetics turbines / housings any more.. not sure about your brand you are using..

 

Yeah, I haven't seen any Turbonetics units in the last year or so, I noticed that the MP T76 is available with a Q-trim wheel and .96 or .81 housings. Wonder what they charge for a pair of the .81's?


---==Temio Williams
Yuba City, CA

 

1 to 1 gear with 26" tall tire at 6500 rpms will give you:
2.73 gears --184mph
3.08's 163 mph
3.23's 156 mph
3.42's 147 mph
3.55's 142 mph
3.73's 135 mph
4.10's 123 mph

1 to 1 gear with 28" tall tire at 6500 rpms give you:
2.73 gears - 198 mph
3.08's gears - 176 mph
3.23's - 168 mph
3.42 - 158 mph
3.55 - 153 mph
3.73 -- 145 mph
4.10 -- 132 mph
4.30 -- 126 mph

 

Tree'd me!! I finally looked around enough to find a better calculator, I appreciate the help!


---==Temio Williams
Yuba City, CA

 

I've got a line on another cam, smaller Duttweiler grind is in but, I don't wanna' be doin' alot of things twice. Check it out:

Grind # CS 4875S / 4876S SR112+4
Lift w/1/5's -- .577" / .583"
Dur. @ .050" -- 248*/254*
LSA: 112.0
I.O. - 16BTDC I.C. - 52ABDC
E.O. - 63BBDC E.C. - 11 ATDC

More duration at .050", still relatively tame lift numbers which suits me just fine. How 'bout the spool with this one?


---==Temio Williams
Yuba City, CA